The primary objectives of the study are to assess the safety and efficacy of rhFIX in previously treated patients. Secondary objectives are to estimate the pharmacokinetic parameters, including recovery and half-life, of rhFIX administered as an intravenous infusion, to evaluate the pharmacokinetic parameters of rhFIX in comparison to pooled human plasma product Mononine to evaluate the efficacy and safety of rhFIX in treating acute bleeding episodes and to evaluate the efficacy and safety of rhFIX in controlling bleeding during and after surgical procedures.